Board Game Arena

I am planning to run a series of monthly Hive tournaments and am looking for player input on the formats. I've set up the first, here https://en.boardgamearena.com/#!tournament?id=8200. The things which are open for discussion are:

The Variants: There are 16 possible rules variations for a Hive game on BGA. Of those 4 are out of the question because they are flawed but that still leaves a fairly long list. The more obvious options are:
Standard Pieces + tournament opening (I've set up the first one on this basis)
Pillbug + standard opening
Ladybird + tournament opening
Mosquito + tournament opening
Ladybird, Mosquito, Pillbug + tournament opening
Do players have strong feelings one way or the other.

There is also the question of format for the tournament. I've got a strong preference for Swiss, as this allows everyone to play through to the end of the tournament, but am interested in how many rounds players might prefer.
In terms of time I've found 2 days is a bit tight so have gone with 3 days, but wonder if people find that easy or difficult. Organising a real-time engagement seems to difficult to co-ordinate with players in widely different time zones.
This first tournament is open to everyone. In Chess its common to divide tournaments based on player ratings. That way people with lower ratings do not have to put up with being completely outplayed and have a fairer chance in their division. How would people feel about splitting events; so Good and above in one? My feeling is there are not enough players but I wanted to solicit responses to the idea.

36 hours for a turn.based tourney is a recipe for timeouts.

My favorite time schedules are

15 days per match for single elimination
15 days per match for round robin
7 days per match for swiss

As maximum number of participants for swiss I like 2^(rounds-2)

Thanks for your comments.
Dudi you suggested, that you would look for 2 more rounds than required to determine a winner, so 7 presumably in the case of 24 players?
Would you have a preference for round robin over Swiss?

Timing is obviously the most difficulty, 15 days, or even 7 days, would be too long for a monthly tournament, allowing only 2 or 3 rounds. To permit 6 rounds (I would think the minumum) would require no more than 5 days. Do you think that would still lead to a lot of timeouts?

Sorry if this question is out of topic, but how ties work during hive online tournaments?

I do not know how they work in KO tournaments, but they simply score half a point in Swiss or Round Robin.